1. Field of the Invention
The present invention relates to a temperature-indicating, printable medium and a label forming device using the medium, wherein the temperature-indicating medium changes color in response to changes in ambient temperature.
2. Description of the Related Art
Tape that has the capacity to change color due to ambient temperatures is well known in the art. By affixing this tape to an object, it is possible to visually detect changes in temperature changes around the object or changes in the temperature of the object itself. For example, beer cans and the like using this tape have been sold on the market. The tape, which is fixed to the beer can, changes color based on the ambient temperature of the can, revealing to what degree the beer in the can is chilled. However, in order to print letters, symbols, or other characters on such a tape that changes color due to changes in ambient temperature, the tape must be custom-ordered from a specialist. Hence, it is costly and time-consuming to obtain this tape.
Japanese Utility Model Publication No. 2559473 discloses a tape-like label forming device for producing a tape that changes colors according to changes in ambient temperature. The device employs a tape-like printing medium that includes a double-sided tape portion having a layer with a temperature-indicating material; and a printing tape portion on which characters such as letters and symbols are printed.
The tape-like label forming device according to the publication described above succeeds in eliminating the time and costs required for special ordering a temperature-indicating tape that has printed desired characters or symbols. However, since a layer with the temperature-indicating material is provided in the double-sided tape portion of the tape-like printing medium and characters can be printed on a printing tape portion of the printing medium, the characters must be printed in the same color as the temperature-indicating material in order to assimilate the characters in the material. Note that the tape-like label thus produced is used, for example, to reveal the characters at a temperature of a certain degree and conceal the characters at a temperature above or below this degree. Accordingly, the device proposed in Japanese Utility Model Publication No. 2559473 has a limitation regarding what colors can be used for the characters and the temperature-indicating material. In addition, the tape-like printing medium can only be used for determining temperatures above a certain degree or below a certain degree. Further, before producing the tape with this device, it is impossible to tell how the tape will change based solely on the external appearance.